Crashproof liquid confining receptacle



NOV. 18, 1947. w, D BRADLEY 2,430,905

CRASH-PROOF LIQUID CONFINING RECEPTACLE Filed March 25. 1944 INVENTOR.MWA/f /lfy BY my@ ATTORNEY Patented Nov. 18, 1947 CRASHPROOF LIQUIDCONFIN ING RECEPTACLE Wayne D. Bradley, South Bend, Ind., assignor toUnited States Rubber Company, New York,

N. Y., a corporation of New Jersey Application March 25, 1%?44, SerialNo. 528,142

2 Claims.

l This invention relates to liquid confining tanks, bags, or receptaclesadapted to be dropped from a low-dying airplane to the ground and whichare so constructed thatthey will not spring av leak when they crashagainst the ground.

In warfare and also in peacetimes it may be desirable to employairplanes to supply liquid such as gasoline, oil, or Water to persons onthe ground from an airplane flying above such persons without requiringthe airplane to land.

The present invention therefore contemplates liquid confiningreceptacles such as tanks or bags 1 capable of holding a number ofgallons of liquid,

and which are so constructed that when such areceptacle containingliquid is dropped from a height up to' approximately 150 feet andcrashes upon the ground it will greatly increase its ca-l portion of thereceptacle of Fig. 1.

a method for imparting the corrugations to theN cylindrical materialused in forming the wall The receptacle shown in the drawing has theform o'f a corrugated tube I0 in which the corrugations are formed ofthe annular ribs II and valleys I2. One end of the receptacle I3 which'may be regarded as the bottom is shown as formed of a plurality ofreinforced discs. The opposite end I4 of the receptacle which may beregarded as the top has a central opening through which liquid may beintroduced into the receptacle and removed therefrom.

The corrugated tubular portion IU of thereceptacle is preferably soformed that it has the annular flange I5 at one end thereof to which thebottom disc I3 is firmly adhered or vulcanized,

pacity at the instant of crash, so aspto reduce the rupturing forceexerted at this instant inside the receptacle by the spreading pressureexerted by the confined liquid. This increase in the capacity of thereceptacle when the crash occurs and has a similar flange I6 at theother end of the receptacle to which the top disc I4 is firmly issecured by forming the receptacle with co-rru-A 1 gated walls and byconstructing such walls of rubber or tough plastic material that issufficiently elastic to permit the corrugations to straighten out totheir nearly fully extended condition under the high internal pressureexerted byV the conned liquid at the moment of crash.

The crash-proof liquid confini-ng receptacle of the present inventionmay be given various shapes, having corrugated walls and relatively atclosed ends, but the preferred receptacle is cylindrical in shape withflattened ends and has the` cylindrical walls deeply corrugated so thatthe receptacle may extend lengthwise preferably as much as twice itsnormal length at the instant of crash to thereby lessen the internalpressure` of the conned liquid.

The various features of the present invention will be further understoodfrom the following description when read in connection with theaccompanying drawing illustrating one good practical form oftheinvention.

In the drawing:

Fig. l is a side elevation of a crash-proof'liquid confining receptacleconstructed in accordance with the present invention, showing thereceptacle as it normally appears when filled with liquid;

Fig. 2 is a similar view showing the receptacle of Fig,1 when fullyextended;

Fig. 3 on a larger scale is a longitudinal sectionaly view through theend portions `of the receptacle of Fig. 1; and

Fig. 4 is a vertical sectional view illustrating secured. The top I4 inthe construction shown is provided with the internally threaded ring I1disposed at the center of the disc lIII. It is rmly secured in place atthe center of the disc by embedding the ring il in a mass of rubber orother plastic material I8. This mass is preferably formedv so as toprovide an annular recess at the outer face of the ring around thethreaded opening I9 so that the head of the threaded cap 20 may lie inthis protecting recess' when the cap is screwed tightly in place toconne the liquid within the receptacle. The end discs I3 and I4 areconveniently formed of two or more plies of fabric impregnated withrubber or other plastic material.

It is important that the corrugated walls l0 of the crash-proofreceptacle be made of plastic material which when vulcanized, cured orset in the corrugated condition will have sufficient elasticity, topermit the corrugations to straighten out from the normal liquid conningcondition of Fig. 1 tothe greatly extended condition of Fig. 2. Thisexpansion under the crash condition should preferably be or more.

The material used in forming the corrugated tubular portion I0 of thereceptacle need not be highly elastic but should be capable ofstretching sufciently to accommodate the outward expansion of the valleyportions I2 of the corrugations l nearly to tile diameter of 'theannular ribs II as shown in Fig. 2, to thereby accommodate thestraightening out of the corrugations under the spreading action whichthe confined liquid exerts within the receptacle when lthe crash occurs.The material used in making the corrugated portions I0 of the receptacleshould obviously be strong and tough so that it will not rupture whenthe receptacle crashes and possibly slides some distance along theground as the result of the momentum imparted to the receptacle by thespeed of the airplane that drops the same.

The material used in forming the portion I of the receptacle may benatural rubber, synthetic rubber or thermoplastic or thermosettingmaterials, provided they have the 'required strength and toughness, andelastic character to the extent above indicated, in the finishedcorrugated receptacle, but the choice of such material will depend tosome extent upon whether the receptacle is to contain water or a solventliquid such as gasoline.

As an example of one good practical construction, a crash-proof fueltank having a normal capacity of 7.5 gallons was formed throughout thecorrugated area I0 thereof of a mixture of synthetic rubber comprising80% Hycar and 20% Thiokol. This tank had a wall thickness ranging from.10 to .15 inch and was capable of being dropped from a slowly movingairplane iiying not more than 150 feet from the ground, withoutspringing a leak when it crashed against the ground.

If the receptacle shownlin Fig. 1 of the drawing,

when filled with liquid, is lifted by gripping the same around its upperend and exerting an upward pull it may elongate appreciably. under thisstretching force. T0 prevent this, in the construction shown, thereceptacle is provided with the longitudinally extending elastic straps2| and the ends 22 of wich are firmly secured to the end discs I3 andI4. These straps 2| will prevent the receptacle from extendingappreciably under normal handling conditions but will stretch as shownin Fig. 2 to permit the receptacle to stretch approximately its fulllength under the crash condition. The straps 2| are entirely free fromthe receptacle except at the ends 22 thereof, and since they may tend tosag away from the receptacle near the central portion thereof, theencircling band 23 secured to the straps 2| is provided to hold thesestraps close to the corrugated walls of the receptacle.

One convenient method for corrugating the tu,- bular material to formthe body portion I0 of the receptacle is illustrated in Fig. 4 whereinthere is provided a supporting means such as a table or oor 24, uponwhich is placed upright a relatively heavy cardboard tube 25 having theinternal diameter that is to be imparted to the receptacle of Fig. 1 andapproximately the same length as that of the receptacle shown in Fig, 1.Over this tube 25 is placed a much longer tube 26 formed of unvulcanizedrubber or rubber-like or plastic material such as above described asbeing suitable for use to form the portion I0 of the receptacle. Thistube 2,6 is corrugated step by step as will be apparent from Fig. 4 bylforcing the tube downwardly a predetermined distance to thereby formthe successive corrugations II, I2. Split annular rings 21 of anydesired thickness are provided about the tube 26 to determine thedistance between the successive corrugations, and since these rings 21are split they may be removed from the tube 26 when the corrugations areformed. After the tube 26 has been completely corrugated the end discs 3and III may be adhesively secured to the end flanges I5 and I6respectively as above described. Then the receptacle thus formed may bevulcanized, cured or otherwise treated to set thetube v26 in thiscorrugated condition. After the receptacle is completely formed it maybe filled with water which will serve to soften the'cardboard tube 25 toa fluid mass which may then be removed by pouring this mass out throughthe threaded opening I9.

It will be seen from the foregoing that the crash-proof liquid confiningreceptacle of the present invention is relatively inexpensive t0construct and is well adapted to be' u sed to supply gasoline or otheressential materials to troops or other persons on the ground from anairplane flying overhead at a low altitude.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. An expansible container adapted to hold liquid and withstand theincreased pressure of said liquid on the walls thereof when the liquidloaded container is subjected to a rapid change of motion, saidcontainer comprising flexible walls having a plurality of extensiblecorrugations extending completely around said container, said containerbeing bendable in all directions about an axis encompassed by saidcorrugations, elastic and universally flexible means cooperating withsaid walls and bendable with said walls for retaining said corrugationsin a retracted position when said liquid is in a static condition, andadapted to permit said corrugations to be extended by said increasedpressure of said liquid.

2. An expansible container adapted to hold liquid and withstand theincreased pressure of several gallons of said liquid on the wall thereofwhen the liquid loaded container is subjected to a rapid change ofmotion, said container comprising elastic walls having a plurality ofextensible corrugations extending completely around said container andexpansible in all directions, said container being bendable in alldirections about an axis encompassed by said corrugations, and elasticand universally flexible means cooperatin-g with said walls forresiliently retaining said corrugations in a retracted position whensaid liquid is in a static condition, and said means being bendable withsaid container in all directions and adapted to permit said corrugationsto be extended by said increased pressure of said liquid.

WAYNE D. BRADLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,607,626 Hopkinson Nov. 23, 19262,295,590 Manson et al Sept. l5, 1942 2,225,764 Beal Dec. 24, 19401,452,039 Gravell Apr. 17, 1923 2,186,183 Trumbull Jan. 9, 19401,852,897 Price Apr, 5, 1932 FOREIGN PATENTS Number Country Date 116,935Australia Mar, 25, 1930

